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Mateusz Guzik <mjguzik@gmail.com> says: Open-coded accesses prevent asserting they are done correctly. One obvious aspect is locking, but significantly more can checked. For example it can be detected when the code is clearing flags which are already missing, or is setting flags when it is illegal (e.g., I_FREEING when ->i_count > 0). In order to keep things manageable this patchset merely gets the thing off the ground with only lockdep checks baked in. Current consumers can be trivially converted. Suppose flags I_A and I_B are to be handled. If ->i_lock is held, then: state = inode->i_state => state = inode_state_read(inode) inode->i_state |= (I_A | I_B) => inode_state_set(inode, I_A | I_B) inode->i_state &= ~(I_A | I_B) => inode_state_clear(inode, I_A | I_B) inode->i_state = I_A | I_B => inode_state_assign(inode, I_A | I_B) If ->i_lock is not held or only held conditionally: state = inode->i_state => state = inode_state_read_once(inode) inode->i_state |= (I_A | I_B) => inode_state_set_raw(inode, I_A | I_B) inode->i_state &= ~(I_A | I_B) => inode_state_clear_raw(inode, I_A | I_B) inode->i_state = I_A | I_B => inode_state_assign_raw(inode, I_A | I_B) The "_once" vs "_raw" discrepancy stems from the read variant differing by READ_ONCE as opposed to just lockdep checks. Finally, if you want to atomically clear flags and set new ones, the following: state = inode->i_state; state &= ~I_A; state |= I_B; inode->i_state = state; turns into: inode_state_replace(inode, I_A, I_B); * patches from https://lore.kernel.org/20251009075929.1203950-1-mjguzik@gmail.com: fs: make plain ->i_state access fail to compile xfs: use the new ->i_state accessors nilfs2: use the new ->i_state accessors overlayfs: use the new ->i_state accessors gfs2: use the new ->i_state accessors f2fs: use the new ->i_state accessors smb: use the new ->i_state accessors ceph: use the new ->i_state accessors btrfs: use the new ->i_state accessors Manual conversion to use ->i_state accessors of all places not covered by coccinelle Coccinelle-based conversion to use ->i_state accessors fs: provide accessors for ->i_state fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb fs: move wait_on_inode() from writeback.h to fs.h Signed-off-by: Christian Brauner <brauner@kernel.org> |
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| fs | ||
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| init | ||
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| ipc | ||
| kernel | ||
| lib | ||
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| .cocciconfig | ||
| .editorconfig | ||
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| README | ||
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.